Reading failure among African American children is a longstanding, high impact public health concern. Despite significant advancements in the science of reading and RD these reading difficulties have continued unabated. AA children are underrepresented in studies focused on targeted populations that have significant difficulty with reading acquisition, and are nearly absent in studies focused on RD or LD. This project seeks to advance our knowledge of the mechanisms underlying reading difficulty in AA children, allowing us to distinguish AA children who exhibit a learning or reading disability from those whose reading difficulties arise from other sources (e.g., environment). The proposed studies are designed to investigate mechanisms by which AA children experience reading difficulty that may or may not be due to RD, by using complementary methods to build and evaluate models of typical and atypical reading development among AA children in 1st-5th grades. The specific aims are: Specific Aim 1: To examine the contribution of general verbal ability, dialectal variation, cognitive abilities and poverty to RD, we will investigate a cross-sequential, longitudinal sample of AA children from low and middle SES backgrounds with a range of reading abilities in grades 1-5. We will build a multilevel, mixed-effects (HLM) model of reading development in AA children designed to evaluate the relative contributions of these variables to reading development. Specific Aim 2: To distinguish RD children with underlying LD from those whose RD owes to other factors, we will conduct novel analyses of the sample from Aim 1. We will use latent class modeling to improve our ability to identify children who have RD and to distinguish them from peers who may have reading difficulties not characteristic of RD. Specific Aim 3: To explore the causal effects of general verbal ability and spoken dialect on essential components of reading acquisition. We will use computational modeling and controlled experimental tasks from peers who may have reading difficulties not characteristic of RD. Specific Aim 3: To explore the causal effects of general verbal ability and spoken dialect on essential components of reading acquisition. We will use computational modeling and controlled experimental tasks to test several hypotheses.